Channel bonding with multiple network types

ABSTRACT

Different data communication architectures deliver a wide variety of content, including audio and video content, to consumers. The architectures employ channel bonding to deliver more bandwidth than any single communication channel can carry. In some implementations, different network types may be channel bonded to function as a single logical channel.

CROSS REFERENCE TO RELATED APPLICATIONS

This application claims the benefit of and incorporates by reference:U.S. Provisional Application Ser. No. 61/663,878, filed Jun. 25, 2012,entitled “Channel Bonding-Audio-Visual Broadcast” and ProvisionalApplication Ser. No. 61/609,339, filed Mar. 11, 2012, entitled “Methodand Apparatus for Using Multiple Physical Channels for Audio-VideoBroadcasting and Multicasting.”

TECHNICAL FIELD

This disclosure relates to audio and video communication techniques. Inparticular, this disclosure relates to channel bonding for channels withdifferent network types.

BACKGROUND

Rapid advances in electronics and communication technologies, driven byimmense private and public sector demand, have resulted in thewidespread adoption of smart phones, personal computers, internet readytelevisions and media players, and many other devices in every part ofsociety, whether in homes, in business, or in government. These deviceshave the potential to consume significant amounts of audio and videocontent. At the same time, data networks have been developed thatattempt to deliver the content to the devices in many different ways.Further improvements in the delivery of content to the devices will helpcontinue to drive demand for not only the devices, but for the contentdelivery services that feed the devices.

BRIEF DESCRIPTION OF THE DRAWINGS

The innovation may be better understood with reference to the followingdrawings and description. In the figures, like reference numeralsdesignate corresponding parts throughout the different views.

FIG. 1 shows an example of a content delivery architecture that employschannel bonding.

FIG. 2 shows an example of logic for content delivery using channelbonding.

FIG. 3 shows an example of a content delivery architecture that employschannel bonding.

FIG. 4 shows an example of logic for content delivery using channelbonding.

FIG. 5 shows a timing example.

FIG. 6 shows an example of a content delivery architecture that employschannel bonding.

FIG. 7 shows an example of logic for content delivery using channelbonding.

FIG. 8 shows an example implementation of a distributor.

FIG. 9 shows an example implementation of a collator.

FIG. 10 shows an example of a content delivery architecture thatperforms channel bonding below the transport layer, e.g., at thedata-link layer.

FIG. 11 shows an example of channel bonding at the data-link layer.

FIG. 12 shows an example of channel bonding at the data-link layer.

FIG. 13 shows an example of logic that a data-link layer may implementfor channel bonding at the data-link layer.

FIG. 14 shows an example of logic that a data-link layer may implementfor channel debonding at the data-link layer.

FIG. 15 shows an example variant of the content delivery architecture ofFIG. 6.

FIG. 16 shows an example variant of the content delivery architecture ofFIG. 7.

FIG. 17 graph illustrating characteristics of different network typeswith regard to performance and availability.

FIG. 18 is a schematic illustrating a system channel bonding across twodifferent network types.

FIG. 19 is an illustration of different logical layers that may be usedfor channel bonding.

FIG. 20 is a flow chart illustrating a method for adaptively changingchannel bonding characteristic.

FIG. 21 is a schematic illustrating an in-home network configured tochannel bond different network types.

FIG. 22 is a schematic illustrating a device for in-home networkconfigured to channel bond different network types.

DETAILED DESCRIPTION

FIG. 1 shows an example content delivery architecture 100. Thearchitecture 100 delivers data (e.g., audio streams and video programs)from a source 102 to a destination 104. The source 102 may includesatellite, cable, or other media providers, and may represent, forexample, a head-end distribution center that delivers content toconsumers. The source 102 may receive the data in the form of MotionPicture Expert Group 2 (MPEG2) Transport Stream (TS) packets 128, whenthe data is audio/visual programming, for example. The destination 104may be a home, business, or other location, where, for example, a settop box processes the data sent by and received from the source 102.

The source 102 may include a statistical multiplexer 106 and adistributor 108. The statistical multiplexer 106 helps make datatransmission efficient by reducing idle time in the source transportstream (STS) 110. In that regard, the statistical multiplexer 106 mayinterleave data from multiple input sources together to form thetransport stream 110. For example, the statistical multiplexer 106 mayallocate additional STS 110 bandwidth among high bit rate programchannels and relatively less bandwidth among low bit rate programchannels to provide the bandwidth needed to convey widely varying typesof content at varying bit rates to the destination 104 at any desiredquality level. Thus, the statistical multiplexer 106 very flexiblydivides the bandwidth of the STS 110 among any number of input sources.

Several input sources are present in FIG. 1: Source 1, Source 2, . . . ,Source n. There may be any number of such input sources carrying anytype of audio, video, or other type of data (e.g., web pages or filetransfer data). Specific examples of source data include MPEG or MPEG2TS packets for digital television (e.g., individual television programsor stations), and 4K×2K High Efficiency Video Coding (HVEC) video (e.g.,H.265/MPEG-H) data, but the input sources may provide any type of inputdata. The source data (e.g., the MPEG 2 packets) may include programidentifiers (PIDs) that indicate a specific program (e.g., whichtelevision station) to which the data in the packets belongs.

The STS 110 may have a data rate that exceeds the transport capabilityof any one or more communication links between the source 102 and thedestination 104. For example, the STS 110 data rate may exceed the datarate supported by a particular cable communication channel exiting thesource 102. To help deliver the aggregate bandwidth of the STS 110 tothe destination 104, the source 102 includes a distributor 108 andmodulators 130 that feed a bonded channel group 112 of multipleindividual communication channels. In other words, the source 102distributes the aggregate bandwidth of the STS 110 across multipleoutgoing communication channels that form a bonded channel group 112,and that together provide the bandwidth for communicating the data inthe STS 110 to the destination 104.

The distributor 108 may be implemented in hardware, software, or both.The distributor 108 may determine which data in the STS 110 to send onwhich communication channel. As will be explained in more detail below,the distributor 108 may divide the STS 110 into chunks of one or morepackets. The chunks may vary in size over time, based on thecommunication channel that will carry the chunk, the program content inthe chunk, or based on any other desired chunk decision factorsimplemented in the distributor 108. The distributor 108 may forward anyparticular chunk to the modulator for the channel that the distributor108 has decided will convey that particular chunk to the destination104.

In that regard, the multiple individual communication channels withinthe bonded channel group 112 provide an aggregate amount of bandwidth,which may be less than, equal to, or in excess of the aggregatebandwidth of the STS 110. As just one example, there may be three 30 Mbsphysical cable channels running from the source 102 to the destination104 that handle, in the aggregate, up to 90 Mbs. The communicationchannels in the bonded channel group 112 may be any type ofcommunication channel, including dial-up (e.g., 56 Kbps) channels, ADSLor ADSL 2 channels, coaxial cable channels, wireless channels such as802.11a/b/g/n channels or 60 GHz WiGig channels, Cable TV channels,WiMAX/IEEE 802.16 channels, Fiber optic, 10 Base T, 100 Base T, 1000Base T, power lines, or other types of communication channels.

The bonded channel group 112 travels to the destination 104 over anynumber of transport mechanisms 114 suitable for the communicationchannels within the bonded channel group 112. The transport mechanisms144 may include physical cabling (e.g., fiber optic or cable TVcabling), wireless connections (e.g., satellite, microwave connections,802.11a/b/g/n connections), or any combination of such connections.

At the destination 104, the bonded channel group 112 is input intoindividual channel demodulators 116. The channel demodulators 116recover the data sent by the source 102 in each communication channel. Acollator 118 collects the data recovered by the demodulators 116, andmay create a destination transport stream (DTS) 120. The DTS 120 may beone or more streams of packets recovered from the individualcommunication channels as sequenced by the collator 118.

The destination 104 also includes a transport inbound processor (TIP)122. The TIP 122 processes the DTS 120. For example, the TIP 122 mayexecute program identifier (PID) filtering for each channelindependently of other channels. To that end, the TIP 122 may identify,select, and output packets from a selected program (e.g., a selectedprogram ‘j’) that are present in the DTS 120, and drop or discardpackets for other programs. In the example shown in FIG. 1, the TIP 122has recovered program ‘j’, which corresponds to the program originallyprovided by Source 1. The TIP 122 provides the recovered program to anydesired endpoints 124, such as televisions, laptops, mobile phones, andpersonal computers. The destination 104 may be a set top box, forexample, and some or all of the demodulators 116, collator 118, and TIP122 may be implemented as hardware, software, or both in the set topbox.

The source 102 and the destination 104 may exchange configurationcommunications 126. The configuration communications 126 may travel overan out-of-band or in-band channel between the source 102 and thedestination 104, for example in the same or a similar way as programchannel guide information, and using any of the communication channeltypes identified above. One example of a configuration communication isa message from the source 102 to the destination 104 that conveys theparameters of the bonded channel group 112 to the destination 104. Morespecifically, the configuration communication 126 may specify the numberof communication channels bonded together; identifiers of the bondedcommunication channels; the types of programs that the bondedcommunication channels will carry; marker packet format; chunk, programpacket, or marker packet size; chunk, program packet, or marker packetPID or sequence number information, or any other chunk or bondingconfiguration information that facilitates processing of the bondedchannel group 112 at the destination 104. One example of a configurationcommunication message from the destination 104 to the source 102 is aconfiguration communication that specifies the number of communicationchannels that the destination 104 may process as eligible bondedchannels; identifiers of the eligible bonded channels; statusinformation concerning status of the demodulators 116, e.g., that ademodulator is not functioning and that its corresponding communicationchannel should not be included in a bonded channel group; channelconditions that affect bit rate or bandwidth; or any other informationthat the source 102 and the distributor 108 may consider that affectsprocessing of the data from the sources into a bonded channel group.

FIG. 2 shows an example of logic 200 for content delivery using channelbonding that the architecture 100 described above may implement inhardware, software, or both. Additional detailed examples are providedbelow, particularly with regard to marker packets and other options.

In FIG. 2, input sources receive program data (202). The program datamay be received from any content provider, and may include any desiredaudio, visual, or data content, including cable television programming,streaming music, file transfer data, as just three examples. The inputsources provide the program data to the statistical multiplexer 106(204), which multiplexes the program data to generate the sourcetransport stream (STS) 110 (206).

The source 102 provides the STS 110 to the distributor 108 (208). Thedistributor 108 reads bonding configuration parameters (210). Thebonding configuration parameters may specify the number of communicationchannels in the bonded channel group 112, the communication channelsthat may be included in the bonded channel group 112, the type ofcommunication channels that may be included in the bonding channel group112, the program sources eligible for bonding, when and for how longcommunication channels and program sources are available for channelbonding, bonding adaptation criteria, and any other parameters that mayinfluence how and when the distributor 108 pushes program data acrossthe communication channels in the bonded channel group 112. Thedistributor 108 sends the program data to the communication channels inthe bonded channel group 112 (212). Specific examples of how thedistributor 108 accomplishes this are provided below. The source 102thereby communicates program data to the destination 104 across themultiple communication channels in the bonded channel group 112 (214).

At the destination 104, the demodulators 116 receive the program dataover the communication channels (218). The demodulators 116 provide therecovered program data (optionally after buffering) to the collator 118.The collator 118 analyzes group information, sequence information, PIDs,and any other desired information obtained from the data packetsarriving on the communication channels and creates a destinationtransport stream (DTS) 120 from the recovered program data (220). TheDTS 120 may convey the program packets in the same sequence as the STS110, for example.

The collator 118 provides the DTS 120 to the TIP 122 (222). The TIP 122reads data selection parameters (224). The data selection parameters mayspecify, for example, which audio/visual program is desired, and may beobtained from viewer input, from automated selection programs orprocesses (e.g., in a digital video recorder), or in other ways.Accordingly, the TIP 122 filters the DTS 120 to recover the programpackets that match the data selection parameters (e.g., by PIDfiltering) (226). The TIP 122 thereby generates a content output thatincludes an output packet stream for the selected program. The TIP 122delivers the generated content to any desired device 124 that consumesthe content, such as televisions, smart phones, personal computers, orany other device.

Several channel bonding processing options are discussed next. Someoptions make reference to marker packets (MPs) inserted into the datastreams going to the destination 104 over the communication channels.The marker packets may be MPEG2 TS packets, for example, with anidentifier that flags them as MPs. In the first option, the distributor108 adds marker packets on a per-channel basis, for example in around-robin manner. In the second option, the distributor 108 generatesand adds markers on a per-chunk basis, for example in a round-robinmanner at chunk boundaries. In the third option, when packets from thesame program will be routed to multiple communication channels, eachpacket receives a program ID and a sequence ID, and no marker packetsare needed. In the fourth option, spare bits in network frames definedbelow the network layer, e.g., at the data-link layer, carry channelbonding information to the source 104.

Regarding the first option, FIG. 3 shows another example of a contentdelivery architecture 300 that employs channel bonding. In thearchitecture 300, a marker packet (MP) source 302 feeds MPs to thestatistical multiplexer 106. The MP source 302 may provide markerpackets at any frequency. For example, the MP source 302 may provide amarker packet for each communication channel in the bonded channel group112 for every ‘n’ non-marker packets received from the sources, every‘k’ ms, or at some other time or packet spacing frequency. The time orpacket spacing, ‘n’ or ‘k’ may take any desired value, e.g., from n=1packet to tens of thousands of packets, or k=1 ms to 1 second. In otherimplementations, the distributor 108 generates the MPs, rather thanreceiving them in the STS 110.

Fewer marker packets consume less channel bandwidth, leaving more roomfor program data. However, more marker packets increase the ability ofthe destination 104 to adapt to changes in the program data, includingallowing the collator 108 to more quickly synchronize the multiple datastreams across the bonded channel group 112, allowing faster programchannel changes through the TIP 122, and facilitating faster adaptationto changes in the configuration of the bonded channel group 112. Markerpacket insertion may vary depending on any desired parameters. Examplesof such parameters include available buffer sizes; target, average, orworst case recovery time for recovering from transmission errors orother transmission issues; target program channel change latency orother types of latency; and target program frame size.

In FIG. 3, the distributor 108 pushes packets to the modulators 130 on around-robin basis, starting with any desired modulator 130. Morespecifically, the distributor 108 may communicate packets on around-robin basis to each communication channel in the bonded channelgroup 112, one packet at a time. In other implementations describedbelow, the round-robin distribution may be done n-packets at a time,where ‘n’ is greater than 1. However, for the example shown in FIG. 3,the distributor 108 pushes one packet at a time in a round-robin manneracross the communication channels that compose the bonded channel group112. Accordingly, given the example STS 110 packet stream of {MP-0,MP-1, MP-2, 1-0, 1-1, 2-1, 2-2, n-0}, the distributor 108 pushes:

MP-0 to channel 1, MP-1 to channel 2, MP-2 to channel 3; then

pkt 1-0 to channel 1, pkt 1-1 to channel 2, pkt 2-1 to channel 3; then

pkt 2-2 to channel 1, pkt n-0 to channel 2, and so on.

The MP source 302 may provide MPs to the statistical multiplexer 106 ata selected priority level, such as a highest available priority level,or a higher priority level than any other packets arriving from theprogram sources. Furthermore, the number of MPs in a set of MPs maymatch the number of communication channels in the bonded channel group112. For example, when there are seven (7) communication channels in thebonded channel group 112, the MP source 302 may provide seven highestpriority MPs to the statistical multiplexer 106. The statisticalmultiplexer 106 may then output the high priority MPs immediately nextin the STS 110, so that the group of seven MPs arrive in sequence at thedistributor 108. As a result of the packet-by-packet round-robindistribution, one of each of the seven marker packets correctly ispushed to one of the seven communication channels in the bonded channelgroup 112 to flag a stream of program packets that follow each MP.

The statistical multiplexer 106 or the distributor 108 or the MP source302 may give the MPs a special identifier, such as a unique PID (e.g.,MARKER_PID) that flags the MPs as marker packets. Any other desiredcontent may be present in the MPs. As examples, the MPs may include achannel number and group number. The channel number may identify thecommunication channel that sent that MP (e.g., channel 0, 1, or 2 for abonded channel group 112 of three communication channels). The channelnumber provides a type of sequence number that identifies, the first,second, third, and so on, communication channel in sequence to which thedistributor 108 has sent program packets. The channel number, in otherwords, identifies a bonded channel sequence of distribution of programpackets to the communication channels in the bonded channel group.

The group number may identify which set of MPs any particular MP belongsto, and the source 102 may increment the group number with each new setof MPs (e.g., every three MPs when there are three communicationchannels in the bonded channel group 112). The group number may alsofacilitate packet alignment, when, for example, jitter or skew is largerthan the gap between inserted packets.

Note that the distributor 108 need not have any special knowledge of theMPs. Instead, the distributor 108 may push packets on a round-robinbasis to the communication channels, without knowing or understandingwhat types of packets it is sending. However, in other implementations,the distributor 108 may in fact analyze and manipulate the packets thatit distributes, to insert or modify fields in the MPS, for example.Additionally, the distributor 108 may generate the MPs, rather thanreceiving them in the STS 110.

The destination 104 processes the marker packets, and may align packetsin a fixed order from the demodulators 116 to form the DTS 120. Thedestination 104 may include First In First Out (FIFO) buffers 304, orother types of memory, to counter jitter/skew on the communicationchannels, and the resultant mis-alignment in reception of packets acrossthe various communication channels. The FIFOs 304 may be part of thecollator 118 or may be implemented separately. A FIFO may be providedfor each communication channel, to provide a set of parallel buffers onthe receive side, for example.

At the destination 104, the collator 118 may drop all packets before aMP from each channel is received. The collator 118 checks the groupnumber of the marker packet in each channel, and drops packets until thecollator 118 has found marker packets with matching group numbers oneach communication channel. When the group numbers do not match, thismay be an indicator to the collator 118 that the skew is larger than thegap between marker packets.

The channel number in the marker packets specifies the sequence ofcommunication channels from which the collator 118 will obtain packets.The collator 118 obtains packets in a round-robin manner that matchesthe round-robin distribution at the source 102. In an example with threecommunication channels in the bonded channel group 112, the collator 118may start by obtaining a packet from the communication channel carryingMP sequence number zero, then moving to the communication channelcarrying MP sequence number one and obtaining a packet, then moving tothe communication channel carrying MP sequence number two and obtaininga packet, then back to the sequence number zero communication channel ina round-robin manner. The collator 118 thereby produces a DTS 120 thatcorresponds to the STS 110. The TIP 122 may then extract the selectedprogram from the DTS 120.

FIG. 4 shows an example of logic 400 for content delivery using channelbonding that may be implemented in hardware, software, or both in theexample architecture 300 described above. Input sources receive programdata (402), and in addition, a MP source 302 may provide MPs (404). Theinput sources and MP source provide the program data and the MPs to thestatistical multiplexer 106 (406), which multiplexes the program dataand MPs to generate the source transport stream (STS) 110 (408).

In particular, the MPs may have a high priority, so that the statisticalmultiplexer 106 inserts them into the STS 110 sequentially without gapsbefore other program data packets. The STS 110 is provided to thedistributor 108 (410). The distributor 108 reads bonding configurationparameters (412). The bonding configuration parameters may specify thatthe distributor 108 should take the round-robin distribution approach,and may specify round-robin distribution parameters. Examples of suchparameters include the round-robin distribution chunk size, e.g.,‘r’packets at a time per communication channel (e.g., ‘r’=1), in whatsituations the distributor 108 should execute the round-robin technique,or any other round-robin parameter. As noted above, the bondingconfiguration parameters may also specify the number of communicationchannels in the bonding channel group 112, the communication channelsthat may be included in the bonding channel group 112, the type ofcommunication channels that may be included in the bonding channel group112, the program sources eligible for bonding, when and for how longcommunication channels and program sources are available for channelbonding, and any other parameters that may influence how the distributor108 pushes program data across the communication channels in the bondedchannel group 112.

The distributor 108 pushes the program data to the communicationchannels in the bonded channel group 112 (414). The source 102 therebycommunicates program data to the destination 104 across the multiplecommunication channels in the bonded channel group 112 (416).

More particularly, the distributor 108 may push the program packets tothe communication channels in round-robin manner. In one implementation,the round-robin approach is a one packet at a time approach. In otherwords, the distributor 108 may take each packet (when ‘r’=1) from theSTS 110 and push it to the next communication channel in sequence. Assuch, the in-order sequence of MPs from the STS 110 is distributed oneMP per communication channel, and is followed by one or more programpackets. The MPs thereby effectively flag for the destination 104 theprogram packets that follow the MPs. After a predetermined number ofprogram packets, the MP source provides another group of MPs that arethen distributed across the communication channels, and the cyclerepeats.

At the destination 104, the demodulators 116 receive the program dataover the communication channels (420). The demodulators 116 provide therecovered program data to buffers (e.g., the FIFOs 304) to help addressjitter/skew (422) on the communication channels. The buffered data isprovided to the collator 118, which may pull packets from the buffers tosynchronize on MPs. The collator 118 analyzes group information,sequence information, PIDs, and any other desired information obtainedfrom the MPs and program packets to synchronize on MPs. Thesynchronization may include finding sequential MPs of the same groupnumber across each communication channel in the bonded channel group112. The collator 118 may then create a destination transport stream(DTS) 120 from the recovered program data (424) by adding packets to theDTS 120 in a round-robin manner across the communication channels in thebonded channel group 112, going in order specified by the channelnumbers specified in the MPs. The DTS 120 may convey the program packetsin the same sequence as the STS 110, for example.

The collator 118 provides the DTS 120 to the TIP 122 (426). The TIP 122reads channel selection parameters (428). The channel selectionparameters may specify, for example, which program is desired, and maybe obtained from viewer input, from automated selection programs orprocesses (e.g., in a digital video recorder), or in other ways.Accordingly, the TIP 122 filters the DTS 120 to recover the programpackets that match the channel selection parameters (e.g., by PIDfiltering) (430). The TIP 122 thereby generates a content output thatincludes an output packet stream for the selected program. The TIP 122delivers the generated content to any desired device 124 that consumesthe content, such as televisions, smart phones, personal computers, orany other device.

FIG. 5 shows a timing example 500 which shows that in someimplementations, the source 102 may address transmit clock variations inthe modulators 130. FIG. 5 shows transmit buffers 502, each of which mayprovide some predetermined depth, such as a depth at least that of thechannel timing variation (e.g., 200 ms). As one example, thecommunication channels may be expected to have the same nominal payloadrates, e.g., 38.71 Mb/s. Further, assume that the transmit clock in eachmodulator is independent, and can vary by plus or minus 200 ppm.

Thus, in the worst case, two channels in a bonded channel group may havea clock difference of 400 ppm. As shown in the example in FIG. 5, thetiming different from channel 1 to channel 2 is 200 ppm, and the timingdifference between channel 1 and channel ‘m’ is 400 ppm. The timingdifference of 400 ppm may amount to as much as one 188 byte MPEG2 TSpacket every 2500 outgoing packets.

Accordingly, the source 102 may insert a compensation packet (which mayhave NULL content) on channel ‘m’ every 2500 packets to cover the extraoutgoing packet, and also insert a compensation packet on channel 2every 5000 packets for the same reason. The compensation packet mayappear, for example, just prior to the MP, or anywhere else in theoutgoing data stream. The destination 104 may identify and discardcompensation packets (or any other type of jitter/skew compensationpacket).

The source 102 may implement a buffer feedback 504. The buffer feedback504 informs the distributor 108 about buffer depths in the transmitbuffers 502. When the buffers run empty, or at other times, thedistributor 108 may insert compensation packets, e.g., before MPs.

FIG. 6 shows another example of a content delivery architecture 600 thatemploys channel bonding. In this second option, the architecture 600includes a distributor 108 that sends data over the communicationchannels in communication units called chunks (but any other term mayrefer to the communication units). The chunks may include one or morepackets from any of the program sources. For example, a chunk may be 1packet, 10 packets, 100 packets, 27 packets, 10,000 packets, 100 ms ofpackets, 20 ms of packets, 30 ms of video data, 5 s of audio data, orany other number or timing of packets or audio/visual content.

The distributor 108 may use the same or different chunk size for any ofthe communication channels. Furthermore, the distributor 108 may changethe chunk size at any time, in response to an analysis of any desiredchunk size criteria. One example of a chunk size criteria is desiredchannel change speed at the destination 104. As the number of packets ina chunk increases, the destination 104 may need to drop more packetsbefore reaching the next chunk boundary, finding the matching MPs, andbeing able to synchronize to the received communication channels. Thechunk size may also depend on compressed video rate or frame size, aswell as target, average, or worst case recovery time for recovering fromtransmission errors or other transmission issues.

In the example in FIG. 6, the statistical multiplexer 106 receivesprogram packets from input sources 1 . . . ‘n’. The program packets maybe MPEG2 TS packets, or any other type of packet. The statisticalmultiplexer 106 creates a STS 110 from the program packets, and the STS110 therefore has a particular sequence of packets multiplexed into theSTS 110 from the various input sources according to the statisticalproperties of the program streams.

For the purposes of illustration, FIG. 6 shows the first six chunks thatthe distributor 108 has decided to send over the communication channels.In particular, the first three chunks are two-packet chunks 602, 604,and 606. The next two chunks are one-packet chunks 608 and 610. The nextchunk is a two-packet chunk 612.

The distributor 108 generates MPs that precede the chunks. Alternativesare possible, however, and some are described below with respect toFIGS. 15 and 16. The distributor 108 may communicate the MPs and thechunks (e.g., in a round-robin manner) across the communicationchannels. In the example of FIG. 6, the distributor 108 sends a MP(e.g., MP-0, MP-1, and MP-2) to each communication channel, followed bya two-packet chunk behind MP-0, MP-1, and MP-2, in round-robin sequence:channel 1, channel 2, channel m, and then returning to channel 1. Thedistributor 108 may start the sequence with any particular communicationchannel.

As is shown in FIG. 6, the communication channels receive MPs and chunksin round-robin manner starting with channel 1 as follows:

Channel 1: MP-0; Channel 2: MP-1; Channel 3: MP-2

Channel 1: chunk 602; Channel 2: chunk 604; Channel 3: chunk 606

Channel 1: MP-4; Channel 2: MP-5; Channel 3: MP-6

Channel 1: chunk 608; Channel 2: chunk 610; Channel 3: chunk 612

Because chunk boundaries are marked with MPs, the distributor 108 mayinsert compensation packets (e.g., NULL packets) without affecting thechannel bonding. In other words, each communication channel may have itsown unique payload rate. Furthermore, MPEG2 TS corruption duringtransmission does not affect other packets.

Each MP may include a channel number and a group number, as describedabove. The channel and group numbers may take a wide variety of forms,and in general provide sequence indicators. Take the example where thechunk size is 100 packets and there are three communication channels A,B, and C, with the distributor 108 proceeding in this order: C, B, A, C,B, A, . . . . The first set of MPs that come before the first 100 packetchunks may each specify group number zero. Within group zero, the firstMP on communication channel C has a channel number of zero, the secondMP on communication channel B has a channel number of one, and the thirdMP on the communication channel A has a channel number of two. For thenext group of chunks of 100 packets, the MP group number for the nextthree MPs may increment to one, and the channel numbers run from zero totwo again.

At the destination 104, the demodulators 116 receive the MPs and chunksfrom each communication channel. Again, individual FIFOs 204 may beprovided to help compensate for jitter and skew.

The collator 118 receives the MPs, and synchronizes on the received datastreams when the collator 118 finds MPs of the same group number and insequence across the communication channels that are part of the bondedchannel group 112. Once the collator 118 has synchronized, it obtainseach chunk following the MPs in order of group number and channelnumber. In this manner, the collator 118 constructs the DTS 120 thatcorresponds to the STS 110. As described above, the TIP 122 executes PIDfiltering on the MPEG2 TS packets to recover any desired program j, andmay discard the other packets.

FIG. 7 shows an example of logic 700 for content delivery using channelbonding, that may be implemented in hardware or software in the examplearchitecture 600 described above. Input sources receive program data(702). The input sources provide the program data to the statisticalmultiplexer 106 (704), which multiplexes the program data to generatethe source transport stream (STS) 110 (706). The distributor 108receives the STS 110 (708).

The distributor 108 also reads bonding configuration parameters (710).The bonding configuration parameters may, for example, specify that thedistributor 108 should take the round-robin distribution approach, andmay specify round-robin distribution parameters. Examples of suchparameters include the round-robin distribution chunk size, e.g., ‘r’packets at a time per communication channel (e.g., r=100), chunk sizeper communication channel, or chunk size variation in time, or variationdepending on chunk size factors that the source 102 may monitor andadapt to over time, in what situations the distributor 108 shouldexecute the round-robin technique, or any other round-robin parameter.As noted above, the bonding configuration parameters may also specifythe number of communication channels in the bonding channel group 112,the communication channels that may be included in the bonding channelgroup 112, the type of communication channels that may be included inthe bonding channel group 112, the program sources eligible for bonding,when and for how long communication channels and program sources areavailable for channel bonding, and any other parameters that mayinfluence how the distributor 108 pushes program data across thecommunication channels in the bonded channel group 112.

In this option, the distributor generates MPs (712) for the chunks ofprogram packets that the distributor sends through the individualcommunication channels in the bonded channel group 112. Thus, forexample, when the bonding configuration parameters indicate a chunk sizeof 100 packets, the distributor generates a MP for each 100 programpackets communicated down the communication channel. As was explainedabove, a MP may include synchronization data, such as a group number andchannel number. As another example, the MP may include timing data suchas a timestamp, time code, or other timing reference measurement.

The distributor 108 sends the MPs and the program data to thecommunication channels in the bonded channel group 112 (714). Thedistributor 108 may send the MPs and program data in a round-robinmanner by communication units of program packets (e.g., by chunks ofprogram packets). The source 102 thereby communicates program data tothe destination 104 across the multiple communication channels in thebonded channel group 112 (716).

More particularly, the distributor 108 may send the program packets tothe communication channels in round-robin manner by chunk. In otherwords, the distributor 108 may take chunks of program packets from theSTS 110 and send them to the next communication channel in the bondedchannel group 112 in a predetermined round-robin sequence (e.g., asspecified in the bonding configuration parameters). As such, an MP isdistributed to a communication channel, and is followed by a chunk ofprogram packets tagged by the MP in terms of group number and channelnumber. The program packets include PID information that identifies theprogram to which each packet belongs. The MPs thereby effectively flagfor the destination 104 the program packets that follow the MPs. Aftereach chunk of program packets, the distributor 108 provides anothergroup of MPs that are then distributed across the communicationchannels, and the cycle repeats. The chunk size may vary in time and bycommunication channel. Furthermore, the source 102 may sendconfiguration communications to the destination 104 to advise thedestination 104 of the bonding configuration and changes to the bondingconfiguration, including chunk size.

At the destination 104, the demodulators 116 receive the program dataover the communication channels (718). The demodulators 116 provide therecovered program data to buffers (e.g., the FIFOs 304) to help addressjitter/skew (720) on the communication channels. The buffered data isprovided to the collator 118, which may pull packets from the buffers tosynchronize on MPs. The collator 118 analyzes group information,sequence information, PIDs, and any other desired information obtainedfrom the MPs and program packets to synchronize on MPs. Thesynchronization may include finding sequential MPs of the same groupnumber across each communication channel in the bonded channel group112.

The collator 118 then creates a destination transport stream (DTS) 120from the recovered program data (722) by adding packets to the DTS 120in a round-robin manner across the communication channels in the bondedchannel group 112. In particular, the collator 118 adds packets to theDTS 120 by chunk of program packets in a round-robin manner across thecommunication channels in the bonded channel group 112. Thus, the DTS120 may convey the program packets to the TIP 122 in the same sequenceas they were present in the STS 110, for example.

The collator 118 provides the DTS 120 to the TIP 122 (724), which readschannel selection parameters (726). The channel selection parameters mayspecify, for example, which program is desired, and may be obtained fromviewer input, from automated selection programs or processes (e.g., in asmart phone content recording application), or in other ways.Accordingly, the TIP 122 filters the DTS 120 to recover the programpackets that match the channel selection parameters (e.g., by PIDfiltering) (728). The TIP 122 thereby generates a content output thatincludes an output packet stream for the selected program. The TIP 122delivers the generated content to any desired device 124 that consumesthe content, such as televisions, smart phones, personal computers, orany other device.

Turning briefly to FIG. 15, that figure shows an example variationarchitecture 1500 of the content delivery architecture 600 in FIG. 6. Inone variation, the distributor may instead issue MP generation signals(e.g., the MP generation signals 1502, 1504, 1506) to the modulators130. The MP generation signal 1502 may be a command message, signalline, or other input that causes the receiving modulator to generate aMP for insertion into the packet stream, e.g., at chunk boundaries. TheMP may include any desired synchronization information, including timestamps, time codes, group numbers, channel numbers, and the like. Themodulator may generate the synchronization information, or thedistributor 108 may provide the synchronization information to themodulator along with the MP generation signal.

In another variation, both the distributor 108 generates MPs and themodulators 130 generate MPs. For example, the distributor 108 maygenerate the MPs for the modulator for CH2 and send MP generationsignals to the modulators for the other channels. Another alternative isfor the distributor 108 to generate MPs for some modulators some of thetime, and to send MP generation signals to those modulators at othertimes. Whether or not the distributor 108 generates the MPs may dependon MP capability information available to the distributor 108. Forexample, the bonding configuration parameters 710 may specify whichmodulators are capable of generating MPs, when, and under whatconditions. Then, the distributor 108 may send the MP generation signalto those modulators at the corresponding times or under thecorresponding conditions. Further, the modulator may communicate withthe distributor 108 to specify MP generation capabilities, and theconditions on those capabilities, such as when and under what conditionsthe modulator can generate MPs, and also what information the modulatorneeds from the distributor 108 to generate the MPs.

Turning briefly to FIG. 16, that figure shows content delivery logic1600 for the architectures described above. FIG. 16 shows again that, inthe architectures described above (e.g., 1500 and 600), the distributor108 may generate MPs, the modulators 130 may generate MPs, or both maygenerate MPs. For example, FIG. 16 shows that for the modulator for CH1,the distributor 108 generates the MPs (1602), e.g., at chunk boundaries.The distributor 108 also generates the MPs for the modulator for CHm(1606). However, for the modulator for CH2, the distributor 108 sends anMP generation signal and any desired synchronization information (1604)to the modulator for CH2. Accordingly, the modulator for CH2 generatesits own MPs for the chunks it receives from the distributor 108. Notealso that any modulator may communicate with the distributor 108 tospecify MP generation capabilities, and the conditions on thosecapabilities, including when and under what conditions the modulator cangenerate MPs, as well as what information the modulator needs from thedistributor 108 to generate the MPs (1608).

Turning now to FIG. 8, the figure shows an example implementation of adistributor 800. The distributor 108 includes an STS input interface802, system logic 804, and a user interface 806. In addition, thedistributor 800 includes modulator output interfaces, such as thoselabeled 808, 810, and 812. The STS input interface 802 may be a highbandwidth (e.g., optical fiber) input interface, for example. Themodulator output interfaces 808-812 feed data to the modulators thatdrive data over the communication channels. The modulator outputinterfaces 808-812 may be serial or parallel bus interfaces, asexamples.

The system logic 804 implements in hardware, software, or both, any ofthe logic described in connection with the operation of the distributor108 (e.g., with respect to FIGS. 1-7 and 10). As one example, the systemlogic 804 may include one or more processors 814 and program and datamemories 816. The program and data memories 816 hold, for example,packet distribution instructions 818 and the bonding configurationparameters 820.

The processors 814 execute the packet distribution instructions 818, andthe bonding configuration parameters 820 inform the processor as to thetype of channel bonding the processors 814 will perform. As a result,the processors 814 may implement the round-robin packet by packetdistribution or round-robin chunk by chunk distribution described above,including MP generation, or any other channel bonding distributionpattern. The distributor 800 may accept input from the user interface806 to change, view, add, or delete any of the bonding configurationparameters 820 or any channel bonding status information.

FIG. 9 shows an example implementation of a collator 900. Thedistributor 108 includes a DTS output interface 902, system logic 904,and a user interface 906. In addition, the collator 900 includesdemodulator input interfaces, such as those labeled 908, 910, and 912.The DTS output interface 902 may be a high bandwidth (e.g., opticalfiber) output interface to the TIP 122, for example. The demodulatoroutput interfaces 908-912 feed data to the collator system logic whichwill create the DTS 120 from the data received from the demodulatorinput interfaces 908-912. The demodulator input interfaces 908-912 maybe serial or parallel bus interfaces, as examples.

The system logic 904 implements in hardware, software, or both, any ofthe logic described in connection with the operation of the collator 118(e.g., with respect to FIGS. 1-7 and 10). As one example, the systemlogic 904 may include one or more processors 914 and program and datamemories 916. The program and data memories 916 hold, for example,packet recovery instructions 918 and the bonding configurationparameters 920.

The processors 914 execute the packet recovery instructions 918, and thebonding configuration parameters 920 inform the processor as to the typeof channel bonding the processors 914 will handle. As a result, theprocessors 914 may implement the round-robin packet by packet receptionor round-robin chunk by chunk reception described above, including MPsynchronization, or any other channel bonding distribution recoverylogic. The collator 900 may accept input from the user interface 906 tochange, view, add, or delete any of the bonding configuration parameters920, to specify which channels are eligible for channel bonding, or toset, view, or change any other channel bonding status information.

The architectures described above may also include network nodes betweenthe source 102 and the destination 104. The network nodes may be type ofpacket switch, router, hub, or other data traffic handling logic. Thenetwork nodes may be aware of the communication channels that they areconnected to, both on the inbound side, and on the outbound side.Accordingly, a network node may receive any particular set ofcommunication channels in a channel bonding group, but need not have amatching set of communication channels in the outbound direction. Inthat case, the network node may filter the received communicationchannel traffic, to drop packets for which the network node does nothave a corresponding outbound communication channel, while passing onthe remaining traffic flow over the outbound communication channels towhich it does have a connection.

In concert with the above, the channel bonding may happen in abroadcast, multicast, or even a unicast environment. In the broadcastenvironment, the source 102 may send the program packets and MPs toevery endpoint attached to the communication channels, such as in a widedistribution home cable service. In a multicast environment, however,the source 102 may deliver the program packets and MPs to a specificgroup of endpoints connected to the communication channels. In thisregard, the source 102 may include addressing information, such asInternet Protocol (IP) addresses or Ethernet addresses, in the packetsto specifically identify the intended recipients. In the unicastenvironment, the source 102 may use addressing information to send theprogram packets and the MPs across the bonded channel group 112 to asingle destination.

A third option is to add, at the source 102, channel bonding data fieldsto the program packets. The channel bonding data fields may be added tothe packet header, payload, or both. The channel bonding data fields mayidentify for the destination 104 how to order received packets to createthe DTS 120. In that regard, the channel bonding data fields may includePID information, sequence information, channel number information, groupnumber information, or other data that the collator 118 may analyze todetermine packet output order in the DTS 120.

In some implementations, a communication head-end may define the programpackets that each source will employ, and therefore has the flexibilityto create channel bonding fields in the program packets. In otherimplementations, the source 102 inserts channel bonding data intoexisting packet definitions (possibly using part of a conventional datafield for this new purpose). For example, in some implementations, eachprogram is formed from multiple MPEG2 PIDs, with each MPEG2 TS packetbeing 188 bytes in size. When packets from the same program will berouted across different communication channels, the source 102 may useheader or payload fields in the MPEG2 TS packets to carry channelbonding fields (e.g., PID and sequence number) in the MPEG2 TS packets.

As one example, the source 102 may add, as channel bonding data, aprogram ID (PID) and sequence number to program packets. The PID may bea 4-bit field that identifies one of 16 different programs. The sequencenumber may be a 12-bit field that identifies one of 4096 sequencevalues. In this implementation, the source 102 need not send MPs.Instead, the channel bonding information (e.g., PID and sequence number)inserted into the program packets provides the destination 104 with theinformation it uses to construct the DTS 120. More specially, thecollator 118 identifies the PIDs and the packets with sequentialsequence numbers for each PID, and creates the DTS 120 with the correctpacket sequence.

Furthermore, the source 102 may also insert the channel bonding datainto lower layer packets. For example, instead of (or in addition to forredundancy), sending MPs defined at or above the transport layer, thesource 102 may instead insert the channel bonding data into framesdefined below the transport layer, such as data-link layer frames orphysical layer frames. As an example, the data-link layer frames may beLow Density Parity Check (LDPC) frames, and the physical layer framesmay be Forward Error Correcting (FEC) frames.

Because such frames are defined at the data-link layer, higher layersmay have no knowledge of these frames or their formats, and generally donot process such frames. Nevertheless, the higher level layers,including the transport layer, may provide bonding information to thedata-link layer that facilitates data-link layer handling of the channelbonding data. Examples of such bonding information includes the amountand type of channel bonding data desired, including the definitions,sizes, and sequence numbering of channel number and sequence numberfields, desired chunk size, number, identification and type ofcommunication channels to bond, or any other channel bondinginformation.

In more detail, in some communication architectures, the data-link layerpackets have spare, reserved, or otherwise ancillary bits. Instead ofhaving the ancillary bit fields remain unused, the system 102 may insertthe channel bonding data in those ancillary bit fields. In otherimplementations, the data-link layer may define its own particularpacket format that includes bit fields specifically allocated forchannel bonding data.

FIG. 10 shows an example of a content delivery architecture 1000 thatperforms channel bonding below the transport layer, e.g., at thedata-link layer or physical layer. FIG. 10 extends the example of FIG. 6for the purposes of discussion, but channel bonding at lower layers mayoccur in any content delivery architecture. In FIG. 10, a protocol stackat the distributor 108 includes multiple layers, including a Physical(PHY) layer 1002, a data-link layer 1004, a transport layer 1006, andany other layers desired 1008. The protocol stack may adhere to the OpenSystems Interconnection (OSI) model, as one example, and the data-linklayer and physical layer structures that may carry channel bondinginformation may include, as examples, Forward Error Correcting (FEC)frames, PHY frames, MAC frames, Low Density Parity Check (LDPC) frames,or IP Datagram frames. However any other protocol stack and structuretypes may instead be in place to handle channel bonding at a level belowthe level at which the program packets.

The STS 110 provides the program packets to the distributor 108. Theprotocol stack handles the program packets. In particular, the data-linklayer 1004 constructs low level frames that encapsulate program packetsand channel bonding data, and that are sent across the communicationchannels in the bonded channel group 112. One example of the low levelframes is the data-link frame 1010. In this example, the data-link frame1010 includes channel bonding (CB) data, data-link frame (DLF) data, andprogram packets (in particular, the first chunk 602). The DLF data mayinclude the information fields in an already defined data-link layerpacket format. The CB data may include channel number and group numberinformation, or any other information that a MP might otherwise carry.

Higher level layers may (e.g., the transport layer 1006 or other layers1008), as noted above, provide guidance to the data-link layer 1004regarding what bonding information to include in the data-link layerframes. However, this is not required. The data-link layer may do itsown analysis and makes its own decisions concerning what channel bondingdata to add into the data-link layer frames. In that regard, thedata-link layer may read the channel bonding configuration parameters.The data-link layer may also exchange the configuration communications126 with the destination 104, including configuration communications 126with the data-link layer, transport layer, or other layers at thedestination 104.

At the destination 104, a protocol stack 1012 processes the datareceived from the demodulators 116. In particular, the protocol stack1012 may include a data-link layer 1014. The data-link layer 1014receives the data-link layer frames (e.g., the frame 1010) to extractthe program packets and channel bonding data. The collator 118 may thenprocess the channel bonding data as described above to synchronize thecommunication channels in the bonded channel group 112 and build the DTS120.

FIG. 11 shows an example of channel bonding using data-link layer frames1100. In FIG. 11, a data stream 1102 represents, for example, sourcedata prior to packetization. The data stream 1102 may be as examples,data generated by a video camera, microphone, or bytes in a file on adisk drive. A content provider generates a packetized stream 1104, forexample in the form of MPEG2 TS packets 1106. The packets 1106 may takemany different forms, and in the example shown in FIG. 11, the packets1106 include Cyclic Redundancy Check (CRC) data 1108 (e.g., in aheader), and a payload 1110.

FIG. 11 also shows the data-link layer frames 1112. In this example, thedata-link layer frames 1112 include a header 1114 and a payload 1116.The header 1114 may include fields in which, although they arepre-defined for other purposes, the data-link layer 1004 inserts channelbonding data, such as channel number and group number. FIG. 11 shows anexample in which the data-link layer frame 1112 includes an MATYPE field1118 (e.g., 2 bytes), a UPL field 1120 (e.g., 2 bytes), a DFL field 1122(e.g., 2 bytes), a SYNC field 1124 (e.g., 1 byte), a SYNCD field 1126(e.g., 2 bytes), and a CRC field 1128 (e.g., 1 byte). This particularframe format is further described in the DVB S2 coding and modulationstandard, In particular, the data-link layer 1104 may insert the channelbonding information into the MATYPE field 1118.

The framing of the data-link layer 112 is such that program packets aregenerally encapsulated into the payload 1116 of the data-link frame1112, while the channel bonding information is added to the header 1204.However, note the packetized stream 1104 does not necessarily line upwith the data-link layer frames 1112. This is shown by the dashed linesin FIG. 11, with the data-link layer frame 1112 breaking across programpackets. The lack of alignment may be due to timing and packet sizemismatches between various layers in the protocol stack, and because thedata stream 1102 does not necessarily adhere to any fixed timingparameters or data formats.

In some implementations, the architectures may facilitate alignment byinserting packets (e.g., NULL packets) of any desired length, paddingprogram packets (e.g., with NULL data), truncating program packets (orotherwise dropping program packet data), dropping program packetsaltogether, or in other ways. The data-link layer 1004 may execute thealignment in order to fit an integer number of program packets into adata-link layer frame. In some implementations, the data-link layer 1004may communicate with other layers in the protocol stack, or other logicin the source 102, to provide guidance on timing, alignment, chunksizes, or other bonding parameters that may facilitate alignment andchannel bonding at the data-link layer.

FIG. 12 shows an example of channel bonding using data-link layer frames1200. As with FIG. 11, in FIG. 12 a data stream 1102 represents, forexample, source data prior to packetization, and the packetized datastream 1104 arises from the data stream 1102. The data-link layer frame1202 includes a header 1204 and a payload 1206. However, in FIG. 12,data-link layer frame 1202 has been designed to include fieldsspecifically for channel bonding information. In the example in FIG. 12,the header 1204 includes the channel bonding field 1 1208 and thechannel bonding field 2 1210. Other header fields 1212 carry otherheader information. Any number and length of channel bonding fields maybe present in either headers or payload fields in the data-link layerframes to hold any desired channel bonding information.

FIG. 13 shows an example of logic 1300 that a data-link layer in thesource 102 may implement for channel bonding at the data-link layer. Thedata-link layer may provide feedback to higher layers (1302). Thefeedback may inform the higher level layers about alignment, timing, orother considerations that affect how program packets break across or fitinto data-link layer packets.

The data-link layer receives program packets from the higher levellayers (1304). If the data-link layer will force alignment, then it maypad program packets, insert alignment packets, or even drop packets orparts of packets, so that the program packets fit within the data-linklayer frame (1306) in a way that corresponds to the selected channelbonding configuration, including, for example, the chunk size. Thedata-link layer inserts channel bonding information into data-link layerframes (1308). In some implementations, the protocol stack at the source102 does not generate separate marker packets for the channel bondinginformation. That is, the low level communication frames (e.g., thedata-link layer frames) carry the channel bonding information inspecific fields defined in the communication frames, so that no separateencapsulation of the channel bonding information (into marker packets,for example), is needed. Expressed yet another way, the data-link layerframes may have one less layer of encapsulation, e.g., encapsulating thechannel bonding information directly into the low level communicationframe, rather than multiple levels of encapsulation, e.g., encapsulatingthe channel bonding information first into a MP defined, e.g., at thesame protocol level as a program packet, and then the MP into thecommunication frame.

The data-link layer also inserts program packets or chunks of packetsinto data-link layer frames. For example, the program packets may existin the payload field of the data-link layer frames. The markerinformation may specify which packets are present in the data-link layerframe with the marker information (1310). The data-link layer thentransmits the data-link layer frames over a communication channel thatis part of a bonded channel group 112.

FIG. 14 shows an example of logic 1400 that a data-link layer in thesource 102 may implement for channel debonding at the data-link layer.The data-link layer receives data-link layer frames (1402). Thedata-link layer extracts the program packets and the channel bondinginformation from the data-link layer frames (1404). Any padding data inthe program frames, or padding packets may be discarded (1406).

The destination 104 analyzes the channel bonding information tosynchronize across multiple communication channels, as described above(1408). Accordingly, for example, the destination may align to channelbonding sequence information across multiple communication channels.Once synchronized, the destination 104 may construct the DTS 120, forexample by round-robin adding chunks to the DTS 120 from the data-linklayer frames, informed by the channel bonding information in thedata-link layer frames (1410).

One example format for a MP is the following:

CBM_PID: ChannelBondingMarker PID, which may be a reserved PID value fora marker packet. In some implementations, MPs may include adaptationlayer information and follow the MPEG2 TS packet structure, althoughsome or all of the content of the packet will be specific to MP datainstead of, e.g., program data. The bytes in the MP may be assigned asfollows (as just one example):

Byte #1: 0x47 (MPEG2 TS pre-defined sync byte)

Byte #2/3: CBM_PID+TEI=0, PUSI=0, priority=1

Byte #4: SC=1300, AFC=1311 (no payload), CC=0x0

Byte #5: Adaptation_length=‘d183

Byte #6: Flags=0x02, e.g., only private data is present

Byte #7: Private data_length=‘d181

Byte #8: Number of channels in Channel Bonding group

Byte #9/10: CBM_Sequence_Number (CBM_SN)

Byte #11/12/13/14: CBM_SIZE

This generic MPEG2 TS packet syntax is further explained in ISO/IEC13818-1, section 2.4.3.2, “Transport Stream packet layer”.

In some implementations, channels of different network types may also bebonded together. As such, devices with multiple communication interfacesmay utilize additional bandwidth that otherwise would be idle. Further,the device may dynamically adapt to the type of data and availablecommunication interfaces to maximize the quality and reliability of thedata being transmitted.

Several channel bonding processing options have been discussed herein.In the first option, the distributor 108 adds marker packets on aper-channel basis, for example in a round-robin manner. In the secondoption, the distributor 108 generates and adds markers on a per-chunkbasis, for example in a round-robin manner at chunk boundaries. In thethird option, when packets from the same program will be routed tomultiple communication channels, each packet receives a program ID and asequence ID, and no marker packets are needed. In the fourth option,spare bits in network frames defined below the network layer, e.g., atthe data-link layer, carry channel bonding information to the source104. Further other options may exist. However, any of the architecturesor features of these techniques may be used together in conjunction withthe discussed implementations for bonding channels with differentnetwork types.

FIG. 17 illustrates multiple different communication network types thatmay be available on home networks. For example, certain devices may haveone or more of the network types illustrated while other devices mayhave a different combination of communication network types. Further,each communication network type may offer a different tradeoff withregard to performance, availability, and cost. Some strategies areavailable for switching communication from one network to anothernetwork such as IEEE1905, denoted by reference numeral 1710.

In one example, a device may have a PLC interface 1714 and a WiFiinterface 1712. Accordingly, a device may establish communication withanother device on the network through either the PLC interface 1714 orseparately the WiFi interface 1712 depending on which network isavailable at the time. Such switching capabilities are denoted byreference numeral 1716. However, a number of different network types mayalso be used in a channel bonding scenario. Through channel bonding,communication may be established through multiple communication networktypes at the same time. Packets and/or communication units (e.g. chunks)may be distributed across multiple communication networks for the sameinformation stream. For example, a coax communication device may also beused interchangeably with a PLC interface 1714 and the WiFi interface1712, as denoted by reference numeral 1722.

A schematic of a system 1800 for channel bonding across multiple networktypes is provided in FIG. 18. A first device 1810 may transmitinformation to a second device 1820 through two bonded networks. Thefirst device 1810 may be configured to communicate through a firstnetwork such as a MoCA network 1812 and a second network such as IEEE1901 network 1814. In this implementation, the first network 1812 may bechannel bonded with the second network 1814, such that each packet orcommunication unit of the data stream being communicated between thefirst device 1810 and the second device 1820 are distributed between thefirst channel 1812 and the second channel 1814. The first device 1810may provide different communication unit sizes to each network type, forexample, based on network bandwidth. Further, the first device maydynamically change the bit rate or transcoder rate for eachcommunication channel based on the number and type of channels availableto communicate with the second device 1820.

The first device 1810 may allocate different channel bonding buffersizes for each network type. Further, the system may determine thenetwork buffer size based on attributes of the network type. Theattributes may include bit rate, availability, signal strength, powerconsumption, or reliability. In addition, the first device 1810 maycommunicate with the second device 1820 to determine network typesavailable to the second device 1820 for communication, as well as,preferences stored on the second device 1810 for receiving communicationfrom the first device 1810.

In some implementations, the first device 1810 may determine thatcertain content is high priority content. The first device 1810 mayidentify high priority content, for example, based on data stored in themarker packet. In this scenario, the first device 1810 may choose tosend a communication unit having a high priority content through aparticular network type. For example, the first device 1810 may sendhigh priority data through a specific network type that has a certainlevel of reliability, or at least the highest reliability of theavailable communication channels. Alternatively, the first device 1810may be configured to send high priority communication units throughmultiple channels redundantly. As such, the communication unit may besent through multiple different network types redundantly. High prioritydata may include information such as base layer packets or I-framepackets of video streams.

FIG. 19 illustrates one implementation of the control scheme for achannel bonding system. The system 1900 may be configured to communicatethrough a plurality of networks 1926. The networks may include WiFi,IEEE 1901, MoCA, Ethernet, or other similar networks including, but notlimited to, all those discussed herein. Further, in someimplementations, this concept may be extended to additional networktypes including 3G, 4G, and LTE or any other wired or wireless network.Each network is controlled by the corresponding physical layer 1924.Each physical layer is connected to a media access control layer 1922(MAC). Often the MAC layer is software that controls the physical layer.The MAC layer often provides a common interface 1920 that is similar toother MAC layers. The interface 920 allows for increasedinterchangeability between communications sent to each network type.

In the implementation shown, the MAC interfaces may be connected to IEEE1905.1 MAC abstraction layer 1914 for controlling home networks. Assuch, the MAC abstraction layer 1914 may communicate and receive datathrough a channel bonding application layer 1910. The channel bondingapplication layer 1910 may communication with the MAC abstraction layer1914 through a channel bonding adaptation layer interface 1912.

The channel bonding adaptation layer 1910 may determine communicationunit and/or packet distribution and insert marker packets. Examples oftechniques for distributing packets among communication channels aredescribed throughout this application. Further, the channel bondingadaptation layer 1910 may determine packet distribution based on channelconditions, such as the bit rate of each channel. This information maybe received from the MAC abstraction layer 1914 through the channelbonding application layer interface 1912. The channel bonding adaptationlayer 1910 may also configure the channel bonding group and adaptivelysend packets to different channels based on changing network conditionsor characteristics of the data being passed.

FIG. 20 is a flow chart illustrating the method 2000 for channel bondingacross different network types. The channel boding group may beconfigured by the channel bonding application layer (2010). The bit ratein the channel bonding group may be obtained from the MAC abstractionlayer (2012). Bonding buffers may then be allocated for each channel(2014). The buffers from each channel may be allocated based on the bitrate for that channel. The system may determine bonding characteristics(2016) such as the packet data types, the condition of each channel, andthe buffer fullness for each channel. The system may then tag and assignpackets to each channel based on the determined characteristics (2018).The method may then continue (2020) such that bonding characteristicsare continually monitored and packets are assigned adaptively based onany change in characteristics.

FIG. 21 is a schematic of a home network configured to use adaptivechannel bonding. The home network 2100 may include a gateway 2110 whichmay include a router or modem configured to receive data from outsidethe home network. The gateway 2110 may receive data from, for example,coax, T1, or other network configured to receive information fromexternal sources (e.g. a headend). The home network 2100 may alsoinclude a number of other devices including a first set top box (STB)2112, a PC 2118, a second set top box 2114, a DVR 2116 and a hard drive2120. The first set top box 2112, second set top box 2114, the DVR 2116,and the PC 2118 may all be connected to the gateway 2110 and each otherthrough multiple network interfaces such as MoCA 2122, WiFi 2124, andpower line 2126 to act as a single logical channel. Although thisexample will be described with regard to those three interfaces,multiple additional interfaces may also be used and bonded together invarious configurations.

In this manner, the gateway 2110 may bond together in variousconfigurations the MoCA network 2122, the WiFi network 2124, and thepowerline network 2126. The gateway 2110 can communicate with each ofthe other devices through the bonded channel group. Accordingly, theinformation coming through the gateway 2110 may be assigned tocommunication units and distributed to one or more of the networks 2122,2124, 2126, such that the data may be received by the appropriate deviceon the network. The gateway 2110 may adaptively select the communicationchannel to use based on amount of data and/or the priority of the datato be transmitted, as well as, characteristics of the network for eachcommunication channel. For example, the gateway 2110 may considernetwork characteristics including network availability, networkreliability, bit rate, signal strength and power requirements.

In a similar manner, devices within the network can also communicate inthis fashion. For example, the communication between the first set topbox 2112 and the DVR 2116 may also be facilitated in a channel bondedconfiguration. For example, the set top box 2112 may communicate withthe DVR 2116 by distributing communication units across both the MoCAand WiFi networks adaptively, according to various networkcharacteristics and the type of data being transmitted. In addition, theDVR 2116 may communicate back with the set top box 2112 via a differentchannel bonded configuration using either of the same or differentnetworks available to the DVR 2116. In some implementations, the set topbox 2112 may establish communication with the DVR 2116 and receiveinformation from the DVR 2116 indicating that only MoCA and WiFinetworks are available for communication to the DVR 2116. In this case,the set top box 2112 may adaptively select between the two availablecommunication channels for distributing packets and/or communicationunits adaptively to the DVR 2116. Although it is understood, that whilethe above description illustrates communication between the first settop box 2112 and the DVR 2116, the same communication may be establishedbetween any of the devices within the home network. As such, each devicemay include software and/or hardware for distributing communicationunits as described with regard to FIG. 22.

In some implementations, the gateway 2110 may attempt to communicatewith a device, such as the hard drive 2120. However, the communicationmay only be available through another device on the network, such as aPC 2118. However, in some implementations not all communication networksare transferred through the PC 2118 to the hard drive 2120. Accordingly,while the channel bonding information is distributed and transmittedacross the three bonded communication channels to the PC 2118, the PC2118 may redistribute the communication units/packets across the fewernumber of networks to the device 2120. Alternatively, the gateway 2110may be in communication with the PC 2118 to determine which networks areavailable to the hard drive 2120. As such, the gateway 2110 may selectto provide communication units/packets that will be delivered to thehard drive across certain communication channels that will be passedthrough the PC 2118 to the hard drive 2120.

FIG. 22 is a schematic illustration of a device 2210 which maycorrespond to any of the devices in the previous FIG. 21, such as thegateway 2110, the first set top box 2112, the PC 2118, the hard drive2120, the second set top box 214, or the DVR 2116. Accordingly, eachdevice 2110 may include a processor 2212 configured to receive a streamof data for communication. The stream of data may be received bydistributor 2214. The distributor 2214 may analyze the data stream todetermine data characteristics. In addition, the distributor 2214 mayalso analyze delivery mechanism (e.g. modulator and/or buffer) for eachnetwork. For example, the distributor 2214 may communication with a MoCAdelivery mechanism 2216, a WiFi delivery mechanism 2218, and a powerlinedelivery mechanism 2220.to understand the characteristics for eachnetwork. Based on the data characteristics and the networkcharacteristics, the distributor 2214 may assign the data tocommunication units and/or insert marker packets that are providedadaptively to one or more of the network communication mechanisms (2216,2218, 2220).

In certain video applications, a base layer may be determined to have ahigher priority than other enhanced layers. As such, the base layer maybe determined to be communicated through a particular network having ahigher reliability such as MoCA, while enhanced layers may bedistributed to the other layers based on availability and othercharacteristics such as buffer fullness.

In particular implementations I-frames may be provided over particularnetwork having higher reliability, such as MoCA, whereas B-frames andP-frames may be distributed via other channels based on the availabilityof those channels (e.g. based on bit rate as determined by bufferfullness). In some other implementations, the base layers or I-framesmay be provided across multiple networks if reliability characteristicsof the available networks fall below a predefined level.

The methods, devices, and logic described above may be implemented inmany different ways in many different combinations of hardware, softwareor both hardware and software. For example, all or parts of the systemmay include circuitry in a controller, a microprocessor, or anapplication specific integrated circuit (ASIC), or may be implementedwith discrete logic or components, or a combination of other types ofanalog or digital circuitry, combined on a single integrated circuit ordistributed among multiple integrated circuits. All or part of the logicdescribed above may be implemented as instructions for execution by aprocessor, controller, or other processing device and may be stored in atangible or non-transitory machine-readable or computer-readable mediumsuch as flash memory, random access memory (RAM) or read only memory(ROM), erasable programmable read only memory (EPROM) or othermachine-readable medium such as a compact disc read only memory (CDROM),or magnetic or optical disk. Thus, a product, such as a computer programproduct, may include a storage medium and computer readable instructionsstored on the medium, which when executed in an endpoint, computersystem, or other device, cause the device to perform operationsaccording to any of the description above.

The processing capability of the architectures may be distributed amongmultiple system components, such as among multiple processors andmemories, optionally including multiple distributed processing systems.Parameters, databases, and other data structures may be separatelystored and managed, may be incorporated into a single memory ordatabase, may be logically and physically organized in many differentways, and may implemented in many ways, including data structures suchas linked lists, hash tables, or implicit storage mechanisms. Programsmay be parts (e.g., subroutines) of a single program, separate programs,distributed across several memories and processors, or implemented inmany different ways, such as in a library, such as a shared library(e.g., a dynamic link library (DLL)). The DLL, for example, may storecode that performs any of the processing described above. While variousembodiments of the invention have been described, it will be apparent tothose of ordinary skill in the art that many more embodiments andimplementations are possible within the scope of the invention.Accordingly, the invention is not to be restricted except in light ofthe attached claims and their equivalents.

What is claimed is:
 1. A system comprising: an input interface; outputinterfaces to individual communication channels, wherein the individualcommunication channels comprise different network types; and logic incommunication with the input interface and the output interfaces, thelogic configured to: determine which of the communications channels toemploy together as a bonded channel group; obtain source data from theinput interface; identify certain packets of the source data as highpriority packets; distribute channel bonding information across theoutput interfaces; and distribute the high priority packets redundantlyacross multiple communication channels in the bonded channel group. 2.The system according to claim 1, wherein the logic is configured toallocate a channel bonding buffer for each communication channel, thelogic being configured to select a size of the channel bonding bufferbased on the network type of the communication channel.
 3. The systemaccording to claim 1, wherein the output interfaces connect to anin-home network and the network types include at least two of MoCA,WiFi, powerline, and Ethernet.
 4. The system according to claim 1,wherein the logic is implemented on a gateway.
 5. The system accordingto claim 4, wherein the gateway is configured to communicate with a settop box to receive a communication channel preference from the set topbox, wherein the communication channel preference indicates preferencefor receiving communication, at the set top box, from the gateway. 6.The system according to claim 5, wherein the communication channelpreference from the set top box is a network type.
 7. The systemaccording to claim 5, wherein the communication channel preference isstored on the set top box.
 8. The system according to claim 1, whereinthe logic is implemented on a set to box.
 9. The system of claim 1,wherein the logic is configured to distribute the data in a round-robinmanner across the bonded channel group.
 10. The system of claim 1, wherethe channel bonding information comprises marker packets.
 11. The systemof claim 1, wherein the logic is configured to select a communicationchannel for the high priority packets in response to the communicationchannel having a level of reliability above a threshold level ofreliability.
 12. The system of claim 1, wherein the logic is configuredto select a communication channel for the high priority packets with ahighest reliability of available communication channels of the bondedgroup.
 13. The system according to claim 1, wherein I-frame packets ofthe source data are identified as high priority packets.
 14. The systemaccording to claim 1, wherein base layer packets of the source data areidentified as high priority packets.
 15. A system comprising: an inputinterface; output interfaces to individual communication channels,wherein the individual communication channels comprise different networktypes; and logic in communication with the input interface and theoutput interfaces, the logic being operable to: determine which of thecommunications channels to employ together as a bonded channel group;obtain source data from the input interface; assign packets of thesource data into chunks, wherein a chunk is a set of packets; identifycertain chunks of the source data as high priority chunks; distributethe high priority chunks redundantly across the communication channelsin the bonded channel group.
 16. A method comprising: obtaining a packetstream created by a statistical multiplexer; dividing the packet streaminto communication units, wherein a communication unit contains aplurality of packets; identifying a bonded channel group ofcommunication channels among a set of available communication channels,wherein a first channel of the bonded channel group has a first networktype and a second channel of the bonded channel group has as secondnetwork type different from the first network type; identify certaincommunication units of the packet stream as high priority communicationunits; distributing the high priority communication units redundantlyacross the first channel and the second channel of the bonded channelgroup.
 17. The method of claim 16, further comprising obtaining a bitrate for each communication channel in the channel bonding group. 18.The method of claim 16, further comprising allocating packets tocommunication channels based on a channel condition of a communicationchannel.
 19. The method of claim 16, further comprising allocating abuffer for each channel in the channel bonding group, allocating packetsto communication channels based on buffer fullness.
 20. The method ofclaim 16, where distributing channel bonding information comprises:distributing marker packets across the channel bonding group in advanceof the communication units.